“Something Like a Seismograph . . .” Of all the recording devices that can reveal to an historian the fundamental movements of an economy, monetary phenomena are without doubt the most sensitive. But to recognize their importance merely as symptoms would do them less than full justice. They have been and are, in their turn, causes. They are something like a seismograph, which not only measures the movements of the earth but sometimes provokes them. —Marc Bloch, 19331
